With increasing development of science and technology, various electronic devices (or computers) such as notebook computers, desktop computers or network servers have become indispensable devices in daily lives of people. Generally, during the operation of the electronic device, the temperature of the electronic components of the electronic device gradually increases. The elevated temperature may result in damage of the electronic components. For solving these problems, the electronic device is usually equipped with a heat dissipating mechanism. In accordance with a conventional heat dissipating mechanism, a fan is used to produce airflow to cool the electronic component through convection, or a heat dissipating unit made of a special material is attached on the electronic component to reduce the temperature through thermal conduction. In addition, a water cooling mechanism is one of the effective and common heat dissipating mechanisms.
The operating principles of the water cooling mechanism will be described as follows. Generally, the water cooling mechanism uses liquid (e.g., water or coolant) as the cooling medium, and uses a continuously-running pump to flow the liquid within an applied system along a circulating loop. The liquid flows along sealed pipes. The pipes are distributed to the surfaces of the electronic components (e.g., the central processing unit). When the liquid with the lower temperature flows through the electronic component with the higher temperature, the liquid absorbs the heat from the electronic component to decrease the temperature of the electronic component. Then, through heat exchange, the heat is released from the pipes to the surroundings or another heat dissipating mechanism. Consequently, the temperature of the liquid is decreased. Then, the liquid flows back to the system and flows along the circulating loop to remove the heat.
For example, a rack coolant distribution unit (also abbreviated as Rack CDU) is one of the water cooling devices used in the server. By the distribution unit, the cooling liquid is directly transmitted to plural cold plates of a server rack through plural pipes simultaneously. Consequently, the electronic components (e.g., a central processing unit) on the cold plates are cooled by the cooling liquid. After the cooling liquid is outputted from the distribution unit, the cooling liquid is transmitted through the associated pumps, the sealed loops and the back-end heat exchange mechanisms. Consequently, the cooling liquid is continuously inputted into the server rack to remove the heat from the server rack.
Moreover, an external loop of the distribution device comprises a cooled liquid inlet and a heat liquid outlet. The external loop is extended to the outside of the serve rack and connected with the back-end cooling pipe. The cold plates are arranged in a vertical stack form. Each cold plate also comprises a cooled liquid inlet and a heat liquid outlet. These cold plates are connected with a cooled liquid inlet and a heat liquid outlet of an inner loop in parallel through an expansion pipe within the server rack. Consequently, the cooling liquid in the inner loop and the cooling liquid in the external loop can exchange heat through the distribution device without being mixed together.
For allowing the cooling liquid to be transmitted from the distribution device to the cold plates, the distribution device is equipped with a transport unit (e.g., a pump) and a storage unit (e.g., a water tank). The storage unit is used for storing the cooling liquid of the inner loop. The pump, the water tank and the water pipes are tightly connected with each other in order to prevent from the leakage of the cooling liquid and the damage of the device. Moreover, it is important to confirm the storage amount of the cooling liquid in the water tank. If the storage amount of the cooling liquid is insufficient, the heat dissipating efficiency of the loop is impaired and thus the temperature of the electronic component is too high.
However, since the inner space of the server is limited, the cooling liquid distribution device is usually fixed in the server. Consequently, it is difficult for the user to observe the storage amount of the cooling liquid in the storage unit (e.g., the water tank). Moreover, if the storage amount of the cooling liquid is insufficient, it is difficult for the user to replenish the water tank with the cooling liquid according to the conventional design. For example, the user has to dissemble the water tank from the distribution device to replenish the water tank with the cooling liquid.
Therefore, there is a need of providing an improved cooling liquid distribution device to overcome the drawbacks of the conventional technologies.